Run flake8 tests automatically on ./run_tests.sh

And add a -P option to disable it.

Change-Id: Ie0039217c82acbd9c9071da27027f57263b39f25
Closes-bug: #1237202
Ignore irrelevant secgroup form field errors

When cleaning data from in the security group rule form, remove any
associated error messages that are not related to the actual fields
being saved.  If we are setting a value derived from another field, also
delete the error message associated with that field.

Change-Id: I1eb4835ea2368b62374f230c6293062a2340980d
Closes-Bug:1237128
Merge "Ignore irrelevant secgroup form field errors"
Merge "Run flake8 tests automatically on ./run_tests.sh"